[ostree] build: Don't use += for ACLOCAL_AMFLAGS

[Colin Walters <walters src gnome org>]

commit 211d9c7985c5d02788948e25dec4c17e73c69c2b
Author: Colin Walters <walters verbum org>
Date:   Sat Jan 11 10:02:34 2014 -0700

    build: Don't use += for ACLOCAL_AMFLAGS
    
    It confuses the autotools.

 Makefile-decls.am |    1 -
 Makefile.am       |    2 +-
 2 files changed, 1 insertions(+), 2 deletions(-)
---
diff --git a/Makefile-decls.am b/Makefile-decls.am
index cd28ba2..a57466c 100644
--- a/Makefile-decls.am
+++ b/Makefile-decls.am
@@ -16,7 +16,6 @@
 # Boston, MA 02111-1307, USA.
 
 # Common variables
-ACLOCAL_AMFLAGS =
 AM_CPPFLAGS =
 AM_CFLAGS =
 DISTCHECK_CONFIGURE_FLAGS =
diff --git a/Makefile.am b/Makefile.am
index e202f0d..451237f 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -17,7 +17,7 @@
 
 include Makefile-decls.am
 
-ACLOCAL_AMFLAGS += -I m4 ${ACLOCAL_FLAGS}
+ACLOCAL_AMFLAGS = -I m4 ${ACLOCAL_FLAGS}
 AM_CPPFLAGS += -DDATADIR='"$(datadir)"' -DLIBEXECDIR='"$(libexecdir)"' \
        -DOSTREE_FEATURES='"$(OSTREE_FEATURES)"' \
        -DGLIB_VERSION_MIN_REQUIRED=GLIB_VERSION_2_34 -DGLIB_VERSION_MAX_ALLOWED=GLIB_VERSION_2_34 \